PKHeX/PKHeX.Drawing.Misc/Util/WallpaperUtil.cs

using System.Drawing;
using PKHeX.Core;
using PKHeX.Drawing.Misc.Properties;
using static PKHeX.Core.GameVersion;

namespace PKHeX.Drawing.Misc
{
    public static class WallpaperUtil
    {
        public static Image WallpaperImage(this SaveFile sav, int box) => GetWallpaper(sav, box);

        private static Image GetWallpaper(SaveFile sav, int box)
        {
            string s = GetWallpaperResourceName(sav.Version, sav.GetBoxWallpaper(box));
            return (Bitmap?)Resources.ResourceManager.GetObject(s) ?? Resources.box_wp16xy;
        }

        public static string GetWallpaperResourceName(GameVersion version, int index)
        {
            index++; // start indexes at 1
            var suffix = GetResourceSuffix(version, index);
            return $"box_wp{index:00}{suffix}";
        }

        private static string GetResourceSuffix(GameVersion version, int index) => version.GetGeneration() switch
        {
            3 when version == E => "e",
            3 when FRLG.Contains(version) && index > 12 => "frlg",
            3 => "rs",

            4 when index < 16 => "dp",
            4 when version == Pt => "pt",
            4 when HGSS.Contains(version) => "hgss",

            5 => B2W2.Contains(version) && index > 16 ? "b2w2" : "bw",
            6 => ORAS.Contains(version) && index > 16 ? "ao" : "xy",
            7 when !GG.Contains(version) => "xy",
            8 => BDSP.Contains(version) ? "bdsp" : "swsh",
            _ => string.Empty,
        };
    }
}